It is known that various surfactants have been found to be useful in cleaning compositions, such as shower gels, shampoos, and light duty detergents (e.g., dish detergents) -- compositions in which good foamability is a prerequisite for consumer approval. The surfactants which have been used to the greatest extent in such compositions are anionic surfactants, such as alkyl sulfates, alkyl ether sulfates, sulfonates, sulfosuccinates, and sarcosinates.
Although the use of anionic surfactants in these compositions permits the attainment of desirable characteristics, including good foamability, it would be beneficial to find other surfactants which could provide equal or better performance at a lower cost. However, other known surfactants, such as amine oxides, betaines, and alkanolamides, are either more costly than the anionic surfactants or give poorer performance, e.g., smaller foam volume, when substituted for the anionic surfactants.
It is sometimes advantageous to use mixtures of surfactants in cleaning compositions when the surfactants can serve different functions, e.g., one serving to improve foamability and another serving to adjust viscosity. However, known surfactant mixtures typically provide a compromise between what can be achieved with the surfactant ingredients alone. Thus, e.g., a mixture of (A) a more costly surfactant which provides good foamability, foam density, or viscosity by itself with (B) a less expensive surfactant which provides poorer foamability, foam density, or viscosity by itself will provide an intermediate foamability, foam density, or viscosity.